What is described are methods and apparatus for configuring a logical network of devices. In particular, methods and apparatus for configuring multiple logical networks that share a common transmission medium are presented.
Home network is a phrase often used to refer to the last hundred feet of any consumer-related network. Traditionally, home networks have largely been used to interconnect personal computers (PCs) and computer peripheral devices, such as printers and scanners, within the home, so that the resources of the peripheral devices could be shared among PC users. In addition, home networks have enabled PC users to share access to broadband Internet connections that are linked to the network.
Recent advancements in the development of smart devices and appliances are causing a paradigm shift to occur in the public's perception of the home network. These advanced smart devices now allow users to control and monitor events in such devices as consumer-based appliances, home electronics, and home-security systems. Indeed, the sales of non-PC central processing unit (CPU)-powered devices, such as computer games, telephones, personal digital assistants (PDAs), set top boxes, and other consumer goods, now surpass the sales of PCs.
Like most networks, home networks are either built around a shared wired or a shared wireless medium. Popular wired mediums include category 5 twisted-pair (used with Ethernet-based systems), telephone line (or category 3 twisted-pair), broadband cable, and powerline carrier (PLC), which uses AC power lines to carry network information throughout the home. Several wireless (or radio frequency [RF]) transport elements are emerging for home networking, including IEEE 802.11, HomeRF, Bluetooth™, and standard wireless access protocol (SWAP).
Whether wired or wireless, home networks should be simple to configure and should operate reliably over long periods of time. If the configuration process is not maintenance-free, easy to use, and quick to install new devices, it will not likely be embraced by the public. Another consumer expectation of home networks is that no new wires should have to be installed in the home to network together smart appliances, such as washing machines, microwave ovens, and air conditioners. In most households, this limits the possible media upon which the home network can be based to RF or PLC. While nearly every household has telephone wiring installed, access to this wiring is usually limited to three or four access points within the home. In contrast, most household appliances are directly connected to a PLC, and RF transport elements by their very nature require no wiring.
A problem associated with PLC and RF-based home networks is that the media are not physically constrained to a single home or apartment. With RF-based networks, the number of homes and apartments that can share the medium is constrained only by the strength of the RF transmissions and the sensitivity of the smart device receivers. With PLC-based network, the number of homes and apartments that can share the medium is constrained to the number of households physically attached to a common power line transformer. In many cases, a single transformer may service several hundred households.
To address this problem, the individual households sharing a common PLC or RF physical network can each be serviced by respective secure logical networks that only allow smart devices physically existing within the individual home access to the network. Accordingly, there exists a need for simple, reliable techniques for configuring smart devices that are attached to a common transmission medium to interoperate in separate, secure logical networks. The established logical networks should be secure from “attacks” from other devices connected to the shared physical medium.
As the paradigm shift to non-PC-based home networks begins to occur, it is unlikely that homeowners will install traditional networking elements, such as routers, switches, and control points, into the home. Yet, it will be desirable to configure devices operating in the home network to use many of the complex functions and capabilities available with these traditional networking elements.
For example, a homeowner may wish to install a pair of smart switches and a smart power outlet, and then to configure these devices to operate such that a switch, installed at each door of a room of the house, controls a lamp plugged into the smart outlet. Moreover, it would be desirable for the smart switches to be capable of being installed in locations where existing wiring to other fixtures is already in place, but to be configurable to control only those devices connected into the smart outlet.
Accordingly, there also exists a need for techniques to easily add new or additional smart devices to the home and to configure these devices to join an already established logical network with a minimum of interaction and skill from the homeowner. The techniques should be such that newly or additionally installed devices should be configurable to not interfere with the operation of existing household wiring or to override existing wired connections if the homeowner so desires.
Conventional techniques for configuring individual logical networks typically require that the individual network devices be configured physically, e.g., using switches, to define both a physical address and a network node address for the devices. Other conventional techniques require that a sophisticated device having a user interface, e.g., a PC or a central home controller, be used to assign the network addresses to the smart devices. Home networks requiring such sophisticated devices are often referred to as PC-centric or controller-based networks. Both of these conventional logical network configuration techniques have their drawbacks.
First, conventional techniques that employ physical configuration typically require that the person(s) configuring the network have knowledge of all logical network numbers and all network node numbers currently in use on the physical network. As discussed above, since a PLC physical network may be shared among several households, this technique requires that the logical network numbers and network node numbers in all neighboring homes on the shared PLC must be known. Moreover, such conventional configurable networks are generally not secure, as the established logical networks are open to attacks by persons that deliberately install devices on the logical network whose address is currently in use.
Second, conventional techniques that require PC-centric or controller-based networks require that a relatively expensive PC or controller be installed in the home, and that a sufficiently skilled person carry out the configuration using the PC or controller. Such a conventional PC-centric based system is described in U.S. Pat. No. 6,175,860 to Gaucher, titled “Method and Apparatus for an Automatic Multi-Rate Wireless/Wired Computer Network”.